Buildings typically require multiple utility connections. For example, it is usual to have one connection for water supply, another for conveying away sewage, a third for electricity, a fourth for telephone, a fifth for cable television, and a sixth for a heating fuel, such as natural gas. Additional types of connections, such as for dedicated data processing networks, may also be envisioned. It is usual for each connection to be established separately. Moreover, there is an increasing tendency for such connections to be established underground. Not only do underground connections avoid the undesirable aesthetic effects of visible above-ground connections, but they also in many cases are more protected against disturbance due to freezing, falling trees, or other causes.
The installation of separate underground connections for each utility service multiplies the work required as well as requiring extra space so that the connections can be far enough apart that one can be worked on without disturbing the others.
Consideration has also been given to establishment of multiple utility connections within a single pipe. Thus, for example, efforts have been made to feed a fiber optic cable for telephone or cable TV service through a sewer pipe. To date, however, such efforts have not been sufficiently successful to come into widespread use. Examples of prior art multiple-wall pipes are disclosed in U.S. Pat. No. 4,157,194 and U.S. Pat. No. 4,906,496. However, available multi-channel pipelines are cumbersome to manufacture and/or install and may not provide adequate separation and/or shielding between utility services. Also, they are not optimally adapted to retrofitting existing utility connections.
Therefore, there has remained a need for improved multi-channel pipe structures which could facilitate the making of multiple utility connections through a single conduit.